Since Luke’s green lightsaber is one of the better elements* of ROTJ, I’d prefer it not be re-coloured blue.
*Divorced from the nonsense of the prequels, Luke’s green lightsaber signifies his individuality and distinctiveness from the Jedi who came before him.
There are REASONS some lightsabers are blue and others are green.
In the prequels? Not really. Any such “reasons” are EU retcons that have since been retconned away with the canon reset.